New roof question

[2515R Dude]

I want to replace my roof. I noticed some roof contractors make valley with metal (sorry, i dont know the terms, i guess it is valley flashing but might be wrong) and some just overlap shingles.
Does it make any difference and which one is the way to go in your opinion?

 

[Roadworthy]

As long as you're looking for opinions, I don't use valley flashing at all. I'm a homeowner not a roofer so I can take the time to weave the shingles across the valley. If not properly installed with enough flashing on each side of the valley the roof may leak in a good rain. I put on a new roof to eliminate leaks.

 

[bigtiller]

As long as you're looking for opinions, I don't use valley flashing at all. I'm a homeowner not a roofer so I can take the time to weave the shingles across the valley. If not properly installed with enough flashing on each side of the valley the roof may leak in a good rain. I put on a new roof to eliminate leaks.

That's the way I have done mine also, and I am not a roofer either.

I don't know why all roofing companies don't weave the shingles in the valleys.

 

[Racer4]

Sometimes having metal in the valley is a plus. Leaves don’t hang on it as much as a woven valley.

 

[oldnslo]

I put rubber snow and ice shield in the valleys on my house and then laced the shingles over that being careful to not step or nail in the center of the valley. Maybe overkill but we have frequent freeze thaw cycles during winter so doing everything I could to reduce potential for ice dams backing water under shingles in the valleys.

 

[2515R Dude]

In CA EVERY roof has valley flashing. In 13 years as a real estate appraiser I never saw other way.
Here in KY, 90% or more weave the shingles.
Now i want to put a new roof on my house and need to make an educated decision.

 

[newbury]

When I worked as a roofer in Vt. we always had metal in the valleys.

 

[2515R Dude]

When I worked as a roofer in Vt. we always had metal in the valleys.

Is there any advantages? I guess the right question is: What is the best way of doing it?

 

[yanmars]

I did some roofing years ago for a contractor and my wife had family in the commercial business of roofing. They all used metal valleys. Also tapered it a bit so it was wider at the bottom than at the top to aid snow from sticking/daming and good water flow. Also slicker than asphalt.
I suspect with the speed asphalt/fiberglass roofing is done today it is just faster, cheaper and requires less type of materials etc.
Choice is yours however. Both do work. Certainly make sure there is appropriate and wide enough underlayment in that area and near the gutters.

 

[paulsharvey]

Peel and stick and then weave.

 

[EddieWalker]

Can you even buy metal valleys anymore? For a very long time, installing a metal valley was considered best practice. But it's been years since I've seen one, and nobody is doing it on new roofs anymore in my area of East Texas.

 

[2515R Dude]

Ok, thanks for all replies and advice. My roof is really steep, so I guess either way is good. So, I will do as locals do.
Thanks again.

 

[EddieWalker]

In my area, the biggest issue that I see with roofers is not installing Drip Edge Flashing. I have no idea why this is so common, but I see it almost every day. And it's why fascia and soffits rot out.

 

[paulsharvey]

It's been 15 years ago; but we used to use 18" roll galv 26ga metal, rolled down the valley, and it wasn't really an exposed metal valley, but it wad there. Problem is, 18", minus atleast 1" of each side, your only 6" on either side, which probably isn't enough to do much. Peel and stick, 24", has the advantage of sealing the nails too, where metal didn't. We never used alum or preformed valleys, back when I was doing shingle roofed apartments.

When I redid my roof, it was peel and stick and weave. Note; my roof is a 4 in 12, no snow load, but wind zone of like 130mph (I pulled that out of my butt, it might be 110 mph?)

 

[not2old]

I spent 30 years repairing condos in greater Vancouver B.C. where it rains forever, and chased large numbers of leaks because a roofer wasn't instantly available. I learned lots from working with them. I believe a metal valley is best but don't use a plain "v". Form the valley flashing with a raised center so that as water runs down the slope, it won't run up the other side under the shingles on the other slope. When the water hits the flashing, it is forced to go vertical and will then run down the valley after losing momentum. Leaks in valleys are difficult to find and a metal valley flashing makes repairs easier as it separates the two slopes. With good materials and good labor, a roof will last a long time today and it's best to try to do a good job.

 

[Racer4]

I spent 30 years repairing condos in greater Vancouver B.C. where it rains forever, and chased large numbers of leaks because a roofer wasn't instantly available. I learned lots from working with them. I believe a metal valley is best but don't use a plain "v". Form the valley flashing with a raised center so that as water runs down the slope, it won't run up the other side under the shingles on the other slope. When the water hits the flashing, it is forced to go vertical and will then run down the valley after losing momentum. Leaks in valleys are difficult to find and a metal valley flashing makes repairs easier as it separates the two slopes. With good materials and good labor, a roof will last a long time today and it's best to try to do a good job.

A lot of the old time roofs (I’m talking about roofs that were being replaced back in the 80s & 90s) had that raised ridge in the middle of the valley flashing. True that it helps divert water down the valley. Another function of that was to relieve stress in the valley sheet. It gave a little bit of leeway for movement from one side of the valley to the other.

 

[yanmars]

What Racer4 said is the valley we used. Not a V but more like a W. That raised part in the center of the valley.

 

[ultrarunner]

My 1983 garage roof shingles in good shape even being 20 year comp...

My valley flashing is failing from acidic organic matter mostly Eugenia leaves...

Only time ever had this and maybe the flashing wasn't good but came from roofing supply.

 

[Midniteoyl]

As said by @paulsharvey , peel and stick, self healing, ice and water shield, then lower shingles ran 6" up the 'uphill' side and the upper shingles overlapping down and cut, like in your 2nd photo. This hides and seals all the nails (assuming they are placed correctly), allows a straight runoff onto the lower roof w/o worry that the water will run up under the shingles on the other side, and if any ice damming does occur, the ice and water shield will still protect the sheathing.

 

[jyoutz]

Either way works. As long as it’s done correctly.